Abstract:
Invasive fungal infections are a major health threat with high morbidity and mortality, highlighting the urgent need for rapid diagnostic tools to detect antifungal resistance. Traditional culture-based antifungal susceptibility testing (AFST) methods often fall short due to their lengthy process. In our previous research, we developed a whole-slide imaging (WSI) technique for the high-throughput assessment of bacterial antibiotic resistance. Building on this foundation, this study expands the application of WSI by adapting it for rapid AFST through high-throughput monitoring of the growth of hundreds of individual fungi. Due to the distinct \"budding\" growth patterns of fungi, we developed a unique approach that utilizes specific cell number change to determine fungi replication, instead of cell area change used for bacteria in our previous study, to accurately determine the growth rates of individual fungal cells. This method not only accelerates the determination of antifungal resistance by directly observing individual fungal cell growth, but also yields accurate results. Employing Candida albicans as a representative model organism, reliable minimum inhibitory concentration (MIC) of fluconazole inhibiting 100% cells of Candida albicans (denoted as MIC100) was obtained within 3h using the developed method, while the modified broth dilution method required 72h for the similar reliable result. In addition, our approach was effectively utilized to test blood culture samples directly, eliminating the need to separate the fungi from whole blood samples spiked with Candida albicans. These features indicate the developed method holds great potential serving as a general tool in rapid antifungal susceptibility testing and MIC determination.
摘要:
侵袭性真菌感染是一种主要的健康威胁,发病率和死亡率高。强调迫切需要快速诊断工具来检测抗真菌耐药性。传统的基于培养的抗真菌药敏试验(AFST)方法由于其漫长的过程而常常达不到。在我们之前的研究中,我们开发了一种全载玻片成像(WSI)技术,用于细菌抗生素耐药性的高通量评估.建立在这个基础上,这项研究通过高通量监测数百种单个真菌的生长,使其适应快速AFST,从而扩大了WSI的应用范围。由于真菌独特的“萌芽”生长模式,我们开发了一种独特的方法,利用特定的细胞数量变化来确定真菌的复制,而不是在我们之前的研究中用于细菌的细胞面积变化,以准确确定单个真菌细胞的生长速率。该方法不仅通过直接观察单个真菌细胞的生长来加速抗真菌耐药性的测定,但也产生准确的结果。采用白色念珠菌作为代表性的模式生物,可靠的最低抑制浓度(MIC)的氟康唑抑制白色念珠菌的100%细胞(表示为MIC100)在3h内使用开发的方法获得,而改良的肉汤稀释法需要72h才能获得类似的可靠结果。此外,我们的方法被有效地用于直接检测血液培养样本,消除了从掺有白色念珠菌的全血样品中分离真菌的需要。这些特征表明,所开发的方法具有巨大的潜力,可作为快速抗真菌药敏试验和MIC测定的通用工具。